1. Field of the Invention
The present invention relates to a powdery bonding agent that is soluble in pure aliphatic compounds, that is used for paints, and which contains powdery polymerizate particles based on methacrylic acid esters, as well as to a solution of the polymerizate in aromatic-substance-free petroleum and to a paint prepared from it.
2. Description of the Background
German patent No. 2,060,545 discloses a bonding agent for air-drying paints which is based on a copolymerizate of isobutylmethacrylate, acrylesters of higher alcohols, and small portions of polymer comonomers, as well as hydroxyalkylesters of acrylic and/or methacrylic acid. This bonding agent is soluble in petroleum poor in aromatic components but insoluble in pure-aliphatic petroleum. Because of the necessity of the presence of at least a portion of highly odorous and toxic aromatic substances in the solvent, paints formulated on such a base are suitable for outdoor paints but not for indoor paints. For fast-drying indoor paints, one needs bonding agents that are soluble in odorless, nontoxic pure aliphatic substances.
Solubility in pure aliphatic compounds can be achieved by increasing the share of long-chain alkylesters of acrylic acid and/or methacrylic acid in the structure of the bonding agent; but these bonding agents entail disadvantages that have established limits on their practical use. In the form of granular substances, beads, or powders, they are somewhat sticky, which limits the time that they can be stored. They are inclined toward caking in the case of summertime storage temperatures, which makes it more difficult to handle the solid bonding agent and which delays its dissolution. Of course, one can improve the block-up resistance of the polymerizate, if one increases the amount of isobutylmethacrylate at the expense of long-chain alkylmethacrylate. But then solubility in pure aliphatic solvents is lost. A need therefore continues to exist for a bonding agent which is soluble in pure aliphatic solvents and at the same time does not clot and does not exhibit block-up resistance.